scholarly journals The San Francisco area earthquake of 1989 and implications for the Greater Vancouver area

1990 ◽  
Vol 17 (5) ◽  
pp. 798-812 ◽  
Author(s):  
J. H. Rainer ◽  
A. M. Jablonski ◽  
K. T. Law ◽  
D. E. Allen
Keyword(s):  
San Francisco ◽  
Structural Integrity ◽  
Building Design ◽  
Building Code ◽  
Soil Conditions ◽  
Design Standards ◽  
Damage Prediction ◽  
October 17 ◽  
Lateral Bracing ◽  
Design Earthquake

The earthquake that hit the San Francisco area on October 17, 1989, is reviewed with respect to damage to buildings, transportation facilities, and services. The San Francisco experience underlines that soil conditions and inadequate structural integrity are the two most important factors in the seismic risk to a building and its inhabitants. This earthquake is used as a model for the damage prediction in the Greater Vancouver area from a "design earthquake" that is implied in the National Building Code of Canada. In comparable housing density the expected damage would be somewhat greater than that observed in the San Francisco region in October 1989 because of differences in amplitude of ground motions and building design standards. This study is seen as a first step in the detailed assessment of damage potentials for the Vancouver region, or other similar metropolitan areas. Potential shortcomings in the 1985 National Building Code of Canada were identified in the seismic requirements for non-engineered buildings (Part 9) concerning lateral bracing, beam splice ties over supports, and anchorage and reinforcing of chimneys. Key words: earthquake damage, building code, damage prediction.

THE EVOLUTION OF BUILDING DESIGN STANDARDS

2020 ◽  
Vol 0 (6) ◽  
pp. 119-134
Author(s):  
Denis Mykhaylovskyi ◽  
Bohdan Bondarchuk
Keyword(s):  
Building Design ◽  
Design Standards

Simplified Criteria to Select Ground Response Analysis Methods for Seismic Building Design: Equivalent Linear versus Nonlinear Approaches

2021 ◽  
Author(s):  
Mauro Aimar ◽  
Sebastiano Foti
Keyword(s):  
Seismic Waves ◽  
Site Response ◽  
Building Design ◽  
Soil Conditions ◽  
Response Analysis ◽  
Depth Range ◽  
Ground Response Analysis ◽  
Equivalent Linear ◽  
Acceleration Time Histories ◽  
Soil Deposits

ABSTRACT The possible amplification of seismic waves in soil deposits is crucial for the seismic design of buildings and geotechnical systems. The most common approaches for the numerical simulation of seismic site response are the equivalent linear (EQL) and the nonlinear (NL). Even though their advantages and limitations have been investigated in several studies, the relative field of applicability is still under debate. This study tested both methods over a wide population of soil models, which were subjected to a set of acceleration time histories recorded from strong earthquakes. A thorough comparison of the results of the EQL and the NL approaches was carried out, to identify the conditions in which the relative differences are significant. This assessment allowed for the definition of simplified criteria to predict when the two schemes are or are not compatible for large expected shaking levels. The proposed criteria are based on simple and intuitive parameters describing the soil deposit and the ground-motion parameters, which can be predicted straightforwardly. Therefore, this study provides a scheme for the choice between the EQL and the NL approaches that can be used even at the preliminary design stages. It appears that the EQL approach provides reliable amplification estimates in soil deposits with thickness up to 30 m, except for very deformable soils, but this depth range may be extended at long vibration periods. This result reveals a good level of reliability of the EQL approach for various soil conditions encountered in common applications, even for high-intensity shaking.

scholarly journals Integrity Management of Marine Structures; With Emphasis on Design for Structural Robustness

2018 ◽  
Author(s):  
Torgeir Moan
Keyword(s):  
Structural Damage ◽  
Structural Integrity ◽  
Oil And Gas ◽  
Offshore Structures ◽  
Design Standards ◽  
Limit States ◽  
Fabrication Errors ◽  
Integrity Management ◽  
Operational Errors ◽  
And Control

Based on relevant accident experiences with oil and gas platforms, a brief overview of structural integrity management of offshore structures is given; including an account of adequate design criteria, inspection, repair and maintenance as well as quality assurance and control of the engineering processes. The focus is on developing research based design standards for Accidental Collapse Limit States to ensure robustness or damage tolerance in view damage caused by accidental loads due to operational errors and to some extent abnormal structural damage due to fabrication errors. Moreover, it is suggested to provide robustness in cases where the structural performance is sensitive to uncertain parameters. The use of risk assessment to aid decisions in lieu of uncertainties affecting the performance of novel and existing offshore structures, is briefly addressed.

Benchmark NBC editions for seismic risk management of existing buildings in Canada

2021 ◽  
pp. 1-11
Author(s):  
Reza Fathi-Fazl ◽  
Bessam Kadhom ◽  
Zhen Cai ◽  
Farrokh Fazileh
Keyword(s):  
Risk Management ◽  
Seismic Risk ◽  
Model Building ◽  
National Research Council ◽  
The United States ◽  
Building Code ◽  
Existing Buildings ◽  
Design Standards ◽  
Multi Level ◽  
Seismic Risk Management

The National Research Council Canada recently developed a multi-criteria and multi-level framework for seismic risk management of existing buildings in Canada. One of the key criteria in this framework is benchmark NBC edition, which refers to the applicable edition of National Building Code of Canada (NBC) in which significantly improved seismic requirements were adopted and enforced. Since post-benchmark buildings are expected to demonstrate satisfactory seismic performance, they may be exempt from structural seismic risk assessment. This paper identifies benchmark NBC editions for 17 model building types in Canada. The identification starts by tracking major seismic improvements in the United States benchmark codes and standards. These improvements are then mapped to applicable NBC editions and relevant design standards. Provincial building code editions corresponding to benchmark NBC editions are also identified. The benchmark NBC editions and corresponding provincial building code editions help building owners quickly identify and exempt post-benchmark buildings with acceptable seismic risks and thus allocate resources to the buildings with potentially unacceptable seismic risks.

Modification of seismograph records for effects of local soil conditions

1972 ◽  
Vol 62 (6) ◽  
pp. 1649-1664 ◽  
Author(s):  
P. Schnabel ◽  
H. Bolton Seed ◽  
J. Lysmer
Keyword(s):  
San Francisco ◽  
Ground Surface ◽  
Soil Conditions ◽  
Local Soil ◽  
Geological Conditions ◽  
Soil Deposits ◽  
Time Histories ◽  
Seismic Records ◽  
Local Soil Conditions ◽  
Good Agreement

abstract A procedure for modifying the time histories of seismic records for the effect of local soil conditions is presented. The method is based on a conventional one-dimensional wave-propagation approach with equivalent linear soil properties, extended to practical use for transient motions through the Fast Fourier technique. The validity of the approach is tested against the motions recorded at four soil sites and one rock site during the 1957 San Francisco earthquake. The good agreement between the computed and recorded values indicates that rock motions can be computed from motions recorded on soil deposits, and that the computed rock motions in turn can be used to predict the motion that would have been recorded under different soil and geological conditions. The method is also used to evaluate the probable rock motions in the vicinity of El Centro in the earthquake of 1940 and the ground surface motions that could have been developed on various soil conditions in the same general area.

Evaluation of SCEC CyberShake Ground Motions for Engineering Practice

2019 ◽  
Vol 35 (3) ◽  
pp. 1311-1328 ◽  
Author(s):  
Ganyu Teng ◽  
Jack Baker
Keyword(s):  
Los Angeles ◽  
Ground Motion ◽  
Ground Motions ◽  
Response Spectra ◽  
Building Design ◽  
Empirical Models ◽  
Soil Conditions ◽  
Engineering Practice ◽  
Ground Motion Selection ◽  
Promising Source

This paper evaluates CyberShake (version 15.12) ground motions for potential application to high-rise building design in the Los Angeles region by comparing them against recordings from past earthquakes as well as empirical models. We consider two selected sites in the Los Angeles region with different underlying soil conditions and select comparable suites of ground motion records from CyberShake and the NGA-West2 database according to the ASCE 7-16 requirements. Major observations include (1) selected ground motions from CyberShake and NGA-West2 share similar features, in terms of response spectra and polarization; (2) when selecting records from Cyber-Shake, it is easy to select motions with sources that match the hazard deaggregation; (3) CyberShake durations on soil are consistent with the empirical models considered, whereas durations on rock are slightly shorter; (4) occasional excessive polarization in ground motion is produced by San Andreas fault ruptures, though those records are usually excluded after the ground motion selection. Results from this study suggest that CyberShake ground motions are a suitable and promising source of ground motions for engineering evaluations.

New Standard for Assessment of Structural Integrity for Existing Load-Bearing Structures-Norsok N-006

2009 ◽  
Author(s):  
Gunnar Solland ◽  
Inge Lotsberg ◽  
Lars G. Bjo̸rheim ◽  
Gerhard Ersdal ◽  
Vidar-Andre´ Gjerstad ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Regulatory System ◽  
Life Extension ◽  
Design Standards ◽  
Load Bearing ◽  
Fatigue Design ◽  
Design Life ◽  
Advanced Analysis ◽  
The Cost ◽  
Existing Structure

An increasing number of platforms in the Norwegian continental shelf are reaching their design life. For various reasons these platforms will require an assessment of their structural integrity. When performing these assessments the engineer is faced with tasks where little guidance is found in design standards, for several reasons. The two most important being: 1) The analyses that is performed in a typical assessment of existing structure is often applying very advanced techniques and methodology that seldom is used in design of new structures, as the cost of doing advanced analysis is relatively low compared to replacement of an existing structure, but relatively high compared to moderate additions of e.g. steel in the design of a new structure. 2) Design standards are based on theories, methods and experience for structures in a given design life (e.g. fatigue design and corrosion protection design). When this design life is extended, sound methods for ensuring that the structures are still sufficient safe is needed. Such methods will normally be “condition based design”, where inspection, maintenance and repairs are included in the assessment in integrated way. Such methods are not given in normal design standards. For these reasons a new NORSOK standard is developed that gives recommendation on how to deal with the specific aspects that engineers meet when performing assessments of structures in general, but also specifically for assessment for life extension. The standard is named “Standard for Assessment of Structural Integrity for Existing Load-bearing Structures” and is issued as a NORSOK standard and given the number N-006 [1]. The topics that are covered in the standard include: Shut down and unmanning criteria for platforms not meeting ordinary requirements, specific issues for determination of ultimate capacities by use of non-linear methods, cyclic capacity checks, fatigue life extension, requirements to in-service inspection etc. The paper describes the background and the content of the new standard and it presents examples of recommendations given. The role of the new standard in the Norwegian regulatory system is shown.

Pipeline Response to Slope Movement and Evaluation of Pipeline Strain Demand

2014 ◽  
Author(s):  
Abdelfettah Fredj ◽  
Aaron Dinovitzer
Keyword(s):  
Slope Failure ◽  
Smooth Particle Hydrodynamic ◽  
Slope Movement ◽  
Soil Conditions ◽  
Burial Depth ◽  
Design Standards ◽  
Element Analysis ◽  
Modeling Tools ◽  
Soil Movement ◽  
Codes Of Practice

Pipelines installed on active slopes can be exposed to slope failure mechanisms. The soil movement can introduce substantial axial and bending strains on buried pipeline, and possibly damage. The techniques to predict pipeline displacements, loads, stress or strains are not well described in design standards or codes of practice. The practice of using finite element analysis of soil-pipe interaction has developed in recent years and is proving to be a useful tool in evaluating the pipeline behavior in response to slope movement. A description of advanced pipe soil interaction modeling tools and their validation against full scale trails has been previously presented. This paper describes the ongoing work involved in a study investigating the mechanical behavior of buried pipelines interacting with active slope movement and evaluation of pipeline strain demand. Detailed pipe-soil interaction analyses were completed with a 3D continuum SPH (Smooth Particle Hydrodynamic) model to examine the pipeline behavior and evaluate the pipeline strain demand in relation to key parameters. This includes the effect of soil movement mechanism, pipeline geometry (D/t), material grade, pipeline burial depth and soil conditions and properties. Sample results of the application of the validated 3D continuum modeling process will be presented. The strain demand determined from the analyses were compared with calculated CSA-Z662 strain limit design, local FEA analyses and BS 7910. These results are being used to develop generalized trends in pipeline response to slope movements.

Combined seismic base shear and torsional loading provisions in the 1990 edition of the National Building Code of Canada

1991 ◽  
Vol 18 (6) ◽  
pp. 945-953
Author(s):  
A. M. Chandler
Keyword(s):  
Ground Motions ◽  
Building Code ◽  
Soil Conditions ◽  
Building Structures ◽  
Base Shear ◽  
Ground Acceleration ◽  
Period Range ◽  
Natural Period ◽  
Short Period ◽  
Edge Response

This paper evaluates the earthquake-resistant design provisions of the 1990 edition of the National Building Code of Canada (NBCC 1990) for asymmetric building structures subjected to combined lateral shear and torsional dynamic loadings arising from earthquake base excitation. A detailed parametric study is presented, evaluating the dynamic edge displacement response in the elastic range, for the side of the building which is adversely affected by lateral–torsional coupling. A series of buildings is studied, with realistic ranges of the fundamental natural period, structural eccentricity, and uncoupled frequency ratio. These buildings are evaluated under base loadings arising from a total of 45 strong motion records taken from earthquakes in North America, Mexico, Europe, the Middle East, and Southern Pacific, categorized according to site soil conditions and the ratio a/v of peak ground acceleration to velocity. The latter parameter together with the uncoupled lateral period are found to influence strongly the combined dynamic edge response, with the greatest forces on edge members arising from earthquakes with high a/v ratio in structures with natural periods below 0.8 s. In this case the NBCC 1990 loading provisions significantly underestimate the elastic dynamic response. For buildings with periods longer than 0.8 s, the conservatism of the base shear provisions leads to overestimation of combined dynamic edge response in asymmetric systems, and this is also true in the short-period range for buildings subjected to ground motions with low a/v ratio. The NBCC 1990 provisions are reasonably conservative for short-period systems subjected to ground motions with intermediate a/v ratio. Key words: earthquakes, seismic, design, response, spectra, base, shear, torsional, provisions.

scholarly journals RATIONAL PARAMETERS OF A MULTI-SPAN GREENHOUSE OF BUILDING PRODUCTION FOR SMALL FORMS OF MANAGEMENT

2020 ◽  
Vol 5 (11) ◽  
pp. 41-47
Author(s):  
A. Blazhnov
Keyword(s):  
Building Design ◽  
Energy Costs ◽  
Structural Elements ◽  
Structural Scheme ◽  
Design Standards ◽  
Open Ground ◽  
Steel Consumption ◽  
Building Area ◽  
The Cost ◽  
Cost Of Construction

Growing vegetables in cultivation facilities can significantly increase the yield of products compared to open ground. Information data on greenhouses offered by producers for farms is summarized. The main types of farm greenhouses are identified, and they are compared for possible heat losses during the cold period of the year. It is established that with an equal building area, the area of enclosing structures of multi-span greenhouses is less than that of single-span frame and arch type. The formula for the minimum coefficient of fencing for a multi-span greenhouse, which provides a minimum of energy costs during the heating period, is derived. The structural scheme of the steel frame of a multi-span greenhouse of construction production from rolled profiles is proposed. It allows to significantly reduce the cost of construction of the structure in comparison with the cost indicators of greenhouses of factory delivery. The dependences of steel consumption for structural elements of the frame as a function of load and its construction parameters are obtained. Based on the obtained dependencies, the rational values of the span and step of the block greenhouse racks for snow loads specified in the building design standards of greenhouses are established. For rational values of planning parameters of the cultivation structure, specific indicators of steel consumption and cost per greenhouse frame are given.

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